Device consisting of rotatable and extensible means for conducting electrical current



March 30, 1954 J. F. LARKIN 2,673,966

DEVICE CONSISTING OF ROTATABLE AND EXTENSIBLE MEANS FOR counucwmc ELECTRICAL CURRENT o 2 Sheets-Sheet 1 Filed Dec. 20, 195

March 30, I954 RKIN 2,673,966

J. F. LA DEVICE CONSISTINQ OF ROTATABLE AND EXTENSIBLE MEANSFOR CONDUCTING ELECTRICAL CURRENT 2 Sheets-Sheet Filed Dec. 20, 1950 INVENTOR. 11MB; [fie V675 LAW/{11V ZZ/X/M Patented Mar. 30, 1954 G 0F ROTATABLE AND DEVICE CONSISTIN EXTENSIBLE MEANS FOR CONDUCTING ELECTRICAL CURRENT James Francis Larkin, New York, N. Y. Application December 20, 1950, SerialNo. 201,840

3 Claims. I

This invention relates to electric lamps.

It is an object of the present invention to provide an electric lamp having a vertical support with a rotatable arm supporting a contact member vertically spaced from the base thereof and a telescoping laterally-extending arm carried by the rotatable member so that the arm can be rotated with the rotatable member about the vertical support and a lamp thereon movable by the arm in a circular path and at the same time ad- J'ustable to different radial distances from the vertical support so that the lamp While overhanging the Work being lighted can be easily and readily adjusted for the best distribution of the light upon the work surfaces.

It is another object of the invention to provide a novel and efricient slidable contact arrangement for use in electric lamps and similar devices supporting an electrical outlet wherein the contact members that are stationary are fixed to one sleeve at one end by insulating tubes that extend to the opposite end of the sleeve to support the contact members and wherein the sliding contacts are confined respectively in slidable insulating tubes which are adjustable over the stationary contact members and over the inslidable insulating tubes being fixed to a telescoping sleeve and adjustable with the telescoping sleeve through the first sleeve to alter the length of the electrical outlet arm.

It is another object of the invention to provide a novel and efficient rotatable contact arrangement to permit free rotational adjustment of electrical contacts over fixed rin contacts and to permit the free rotation supporting member on a provide a lamp support having a rotatable member for a lamp outlet which can be adjusted angularly and without Wires extending upwardly through the vertical support becoming twisted or worn and unsafe.

Other objects of the present invention are to provide adjustable contact arrangements for electric lamps and for vertical supports for electrical outlets, which are of simple construction, inexpensive to manufacture, have a minimum number of parts, easy to adjust, provide for continual tight engagement of contacts, compact, adequately insulated, of pleasing appearance and efiicient in use and operation.

For a better understanding of the invention, reference may be had to the, following detailed of an electrical outlet vertical support and to 5 view being, taken on line 4-5 of Fig. 1

Fig. 1 is a fragmentary elevational view of a lamp support and with the laterally-extending swingable outlet arm with electrical contact arrangement embodying the features of the present invention,

Fig. is an enlarged sectional view taken through the rotatable contact arrangement and on line 22 of Fig. 1,

Fig. 3 is a collective and exploded view of the rotatable contact arrangement, the parts thereof being shown in perspective,

Fig. 4 is an enlarged sectional view taken longi tudinaily of the laterally-extending arm and through the slidable contact arrangement, the

Fig. 5 is a perspective view of one of the stationary contact elements of the slidabl contact arrangement and of the means for fixing the stationary contact to one of the telescoping sleeves,

Fig. 6 is an enlarged sectional view taken on line 6-6 of Fig. 5 and through the stationary contact member,

Fig. 7 is a perspective and fragmentary view of the insulating tubes bearing the elongated sliding contact elements of the sliding contact arrangement,

Fig. 8 is a perspective view of the ends of the slidin contact insulating tubes and illustrating the manner in which they are supported in the sliding telescopin sleeve of the sliding contact arrangement,

Fig. 9 is an enlarged transverse sectional view taken on line 9-9 of Fig. 4,

Fig. 10 is a fragmentary vertical view of the rotatable contact arrangement and of the rotatable supporting member to which the laterallyextending sliding contact supporting arm is attached.

Referring now to the figures, 2.! lamp base having feet portions 22 ceptacles 23 by which the lamp can with an electric source. from the base is a having intermediate cal lamp deflector represents a and plug rebe connected Extending upwardly vertical tubular support 24 its length an inverted coni- Fixed to the bottom face of the insulating member 33 by means of screws 34. This thrust bearing 33 is further supported on an inwardly-extending fiange 35 of a tubular member 36 lying within the vertical support tube 24. A vertical shaft 31 has a bottom end bearing 38, rounded to conform to the internal rounded shape of the lower end of the vertical thrust bearing member 33. The vertical shait extends upwardly from the insulating member 28 and through a spacing collar 39. Resting on the spacing collar 39 is the lower end of a T-fitting 4| which has lower and upper insulated bushings 42 and 43 and an insulated screw 4| secures the T-fitting to the shaft that is detachable from bearing 33. The T-fitting extends through the wall of member 3| and is held against rotational displacement therein by an internally-threaded collar 44 to which external telescoping slide connector arm sleeve 45 is threaded, Fig. 4.

The lower insulating member of the rotational contact arrangement has concentric contact rings 46 and 41 lying within the bottoms of respective grooves 33 and 59, Figs. 2 and 3. Cable wires and 52 respectively connect with the contact rings 46 and 41 to supply electric current thereto. These cable wires ti and 52 are connected to the plug receptacle 23 in the base 2|, the cables extending downwardly through the tubular vertical support 24.

The upper insulating annular portions 53 and spective annular grooves insulating member 38 and retain the upper insulating member 29 against lateral displacement from the contact member 38. The annular portions 53 and 54 respectively have openings 55 and 56 to accommodate respectively arcuate contact shoes 5? and 58 having respectively stems 59 and 88 lying within holes 6| and 62 in the insulating member '29. Th stems 58 and 66 have respectively wires 33 and 64 connected thereto which extend into a sleeve 65 of insulation that leads into the T-fitting 4| and outwardly therethrough for connection with stationary contacts 65 and 61 passing respectively through rigidly held insulating tubes 68 and 68 that extend through the telescoping sleeve 45 of slide contact arm arrangement indicated generally at l The member 3| has a top portion 12, Fig. 10, upwardly through which extends shaft 31. A transverse portion 73 is provided in the upwardly extending portion 72 and a nut 14 threaded upon the shaft 31 and rests against a washer on the transverse portion 13. This retains the member 3| and the insulating members on the vertical support 24. On the upper end of the portion 12 is fixed a deflector E6 in which is disposed a lamp bulb ll serving to direct light rays upwardly toward the ceiling. The outer end of the sleeve 45 has a shoulder portion 18 against which a shoulder 19 of an inner telescoping sleeve 88 will abut to limit the outward sliding movement of the inner telescoping sleeve 88. The sleeve 88 is fitted into sleeve II by inserting the same through the inner end thereof and before the outer sleeve 45 is fixed to the internally-threaded collar fitting 44. The small insulating tubes 68 and 69 are secured between separable clampin members 8| and 82 adapted to fit in the end of the sleeve 45 in a tight manner and are held against rotational displacement by set screws 83 entering respectively holes 84 in the separable clamping members to hold the clamping members. Cement may be used to fix the insulating tubes 68 and 89 to the clamping member has depending 54 that lie within the re- 48 and 49 in the lower members and the clamping members to the tube 45 to more adequately secure these parts together so that there will be no play or working of the parts as the sleeve 88 is worked in and out of the sleeve 45.

Within the sleeve 86, are 85 and 86 respectively receiving the stationary contacts 66 and 61 and having longitudinallyextending contact strips 81 and 88. These strips are held against displacement through the tube by having their ends bent over the ends of the tubes in the manner as indicated at 89 and 90. The insulating tubes 85 and 86 are held in the sleeve 88 by separable clamping members 9| and 92, Fig. 8. There is a pair of these members at each end of the sleeve and accordingly the insulating tubes and 86 are held rigidly and parallel to each other. A screw enters the sleeve 80 similar to the screw 83 as shown in Fig. 5 and enters a hole 93 in one of the separable clamping members whereby to hold the clamping members against rotation and axial displacement within the sleeve 88. Cement may be used to secure the members to the sleeve 88 and to the tubes 85 and 86.

Intermediate the length of the tubes 85 and 86, the tubes can be held together by bands 94. On the end of the inner sleeve 80 there is threaded a fitting 95 having wires 98 and 81 which are respectively connected to the metal strip con tacts 8? and 38 as shown in Fig, '7. The fitting 95 supports a lamp socket 98 into which a bulb can be disposed.

It will be seen that the lamp provides for the rotational adjustment of the telescoping sleeves about the vertical support without the necessity of wires being twisted in the vetrical support by the provision of a rotational contact arrangement 28 and that by means of the telescoping contact arrangement H the arm length can be adjusted to locate the lamp on the end thereof at a desired distance from the vertical support.

It should be further apparent that there has been provided contact arrangements wherein the parts thereof are held rigid and tight and wherein every provision is made for insulating the same from each other and that any chance of short circuit of the parts has been brought to a m'nimum.

The stationary contacts 66 and 81 are held rigid and against displacement by the hollow tubes 68 and 69 through which the wires extend and are maintained against being bent by these hollow tubes. The sleeve 86 can accordingly move two insulating sleeves in and out of the sleeve H without interference from wires. The sleeve 80 holds rigidly the tubes 85 and 86 that have the metal strip contacts 81 and 88.

While various changes may be made in the detail construction, it shall be understood that such changes shall be in the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

1. A device of the character described comprising a vertical support, a rotational contact arrangement mounted on the upper end of the vertical support, a thrust bearing depending from the rotational contact arrangement, said rotational contact arrangement having lower and upper insulating members with contacts thereon and with the contacts of one member engageable with the contacts of the other member whereby upon relative rotation of the members a continuous supply of electric current will be delivered, wire means in the vertical support connecting with the contacts of the lower insulating member, an upper structure connected to the upper insulating member and wire means extending from the contacts of the upper insulating member into the upper structure, a vertical shaft seated in the vertical thrust bearing and extending upwardly through the insulating members and into the upper structure, securing means on the upper shaft for securing the shaft to the upper structure, a T-fitting fixed to the shaft withinthe upper structure and connected to the wall thereof, a telescoping contact arrangement fixed to the wall of the upper structure and connected to the T-fitting thereof, said telescoping contact arrangement having interfitting sleeve parts, stationary contacts connected to one part and strip contacts connected to the other part and slidable over the fixed contacts, an electric outlet connected to the outer end of the telescoping contact arrangement, said wiring means extending from the upper insulating member of the rotational contact arrangement extending through the T-fitting and connected with the stationary contacts of the telescoping contact arrangement and further wiring means connected between the sliding strip contact means of the telescoping arrangement and the electrical outlet thereon.

2. A sliding contact arrangement comprising interfitting sleeves respectively having shoulders means to prevent the outward displacement of the sleeves from one another upon the same being extended and to limit the telescopic movement of the sleeves relative to each other, a pair of insulating hollow tubes having respectively cylindrical contacts on the outer ends of the same and clamping means for securing these tubes to one end of one of the sleeves and to hold the same in spaced parallel relationship within the one sleeve, wires extending respectively through the tubes and connected respectively with the contacts, a second pair of hollow tubes spaced from one another to receive the spaced contacts to permit relative sliding movement of the contacts through these latter tubes, metal strip contacts extending respectively through these hollow tubes from one end thereof to the other and adapted to have respectively sliding contact with the respective stationary contacts on the ends of the first insulating tubes and means for clamping the second insulating tubes to the other sleeve and against displacement relative to the other sleeve and wire means extending from the sliding contacts.

3. A device of the character described comprising a vertical support, a rotational contact arrangement mounted on the upper end of the vertical support, a thrust bearing depending from the rotational contact arrangement, said rotational contact arrangement having lower and upper insulating members with contacts thereon and with the contacts of one member engageable with the contacts of the other member whereby upon relative rotation of the members a continuous supply of electric current will be delivered, wire means in the vertical support connecting with the contacts of the lower insulating member, an upper structure connected to the upper insulating member and wire means extending from the contacts of the upper insulating member into the upper structure, a vertical shaft seated in the vertical thrust bearing and extending upwardly through the insulating members and into the upper structure, securing means on the upper shaft for securing the shaft to the upper structure, a T-fitting fixed to the shaft within the upper structure and connected to the wall thereof, a sliding contact arrangement having interfitting sleeves fixed to the wall of the upper structure and connected to the T-fitting, said interfitting sleeves having shoulder means to prevent the outward displacement of the sleeves from one another upon the same being extended and to limit the telescopic movement of the sleeves relative to each other, a pair of insulating hollow tubes having respectively cylindrical contacts on the outer ends of the same and clamping means for securing these tubes to one end of one of the sleeves and to hold the same in spaced parallel relationship within the one sleeve, wires extending respectively through the tubes and connected respectively with the contacts, a second pair of hollow tubes spaced from one another to receive the spaced contacts to permit relative sliding movement of the contacts through these latter tubes, metal strip contacts extending respectively through these hollow tubes from one end thereof to the other and adapted to have respectively sliding contact with the respective stationary contacts on the ends of the first insulating tubes and means for clamping the second insulating tubes to the other sleeve and against displacement relative to the other sleeve and wire means extending from the sliding contacts.

JAMES FRANCIS LARKIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 296,355 Ritchie Apr. 8, 1884 1,607,807 Anderson Nov. 23, 1926 1,782,917 Carlson Nov, 25, 1930 2,116,0 0 Stock May 4, 1938 FOREIGN PATENTS Number Country Date 90,217 Austria Dec. 11, 1922 353,632 Italy Oct. 22, 1937 

